could clack
Verbo regular: clack - clacked- clacked

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could clack
you could clack
he could clack
we could clack
you could clack
they could clack 	I could be clacking
you could be clacking
he could be clacking
we could be clacking
you could be clacking
they could be clacking	I could have clacked
you could have clacked
he could have clacked
we could have clacked
you could have clacked
they could have clacked	I could have been clacking
you could have been clacking
he could have been clacking
we could have been clacking
you could have been clacking
they could have been clacking	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I couldn't clack
you couldn't clack
he couldn't clack
we couldn't clack
you couldn't clack
they couldn't clack 	I couldn't be clacking
you couldn't be clacking
he couldn't be clacking
we couldn't be clacking
you couldn't be clacking
they couldn't be clacking	I couldn't have clacked
you couldn't have clacked
he couldn't have clacked
we couldn't have clacked
you couldn't have clacked
they couldn't have clacked	I couldn't have been clacking
you couldn't have been clacking
he couldn't have been clacking
we couldn't have been clacking
you couldn't have been clacking
they couldn't have been clacking	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I clack?
could you clack?
could he clack?
could we clack?
could you clack?
could they clack? 	could I be clacking?
could you be clacking?
could he be clacking?
could we be clacking?
could you be clacking?
could they be clacking? 	could I have clacked?
could you have clacked?
could he have clacked?
could we have clacked?
could you have clacked?
could they have clacked? 	could I have been clacking?
could you have been clacking?
could he have been clacking?
could we have been clacking?
could you have been clacking?
could they have been clacking? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
couldn't I clack?
couldn't you clack?
couldn't he clack?
couldn't we clack?
couldn't you clack?
couldn't they clack? 	couldn't I be clacking?
couldn't you be clacking?
couldn't he be clacking?
couldn't we be clacking?
couldn't you be clacking?
couldn't they be clacking? 	couldn't I have clacked?
couldn't you have clacked?
couldn't he have clacked?
couldn't we have clacked?
couldn't you have clacked?
couldn't they have clacked? 	couldn't I have been clacking?
couldn't you have been clacking?
couldn't he have been clacking?
couldn't we have been clacking?
couldn't you have been clacking?
couldn't they have been clacking?